Controller.



PATENTED AUG. 29, 1905.

H. E. WHITE. CONTROLLER. APPLICATION FILED APR/I, 1904.

2 SHEETS-SHEET 1.

Inventor,

Hamid E. White.

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HAROLD E. WHITE, OF SOHENEOTADY, NEW YORK, ASSIGNOR TO GEN- ERALELECTRIC COMPANY, A CORPORATION OF NEW YORK.

CONTROLLER.

Specification of Letters Patent.

Patented Aug. 29, 1905.

To all whom it may concern:

Be it known that I, HAROLD E.W1-IITE, a citizen of the United States,residing at Schenectady, county of Schenectady, State of New York, haveinvented certain new and useful Improvements in Oontrollers,of which thefollowing is a specification.

My invention relates to systems of motor control, and more particularlyto the control of motors operated on a multivoltage system of electricaldistribution. The purpose of such operation is to obtain a wide range ofspeed variation with a minimum size of motor, and in order to accomplishthis it is usual to employ, in addition to the starting resistance,which is included in series with the motor-armature, a field resistancein series with the field-winding and to vary these resistances and thecircuit connections. so as to obtain the desired speed variations. Asystem of this type is disclosed in Patent No. 7322M, granted to E. R.Whitney June 30, 1908'.

The presentinvention has to do particularly with the controller by whichthe necessary changes in circuit connections are made.

I have found that in the operation of controllers heretofore employedfor making these changes in circuit connections when thecontroller-cylinder is rotated far enough to connect the motor to thehigh-potential mains and is then suddenly returned to a low-potentialposition the momentum of the motor-armature, together with the slownessof the field in building up, causes the armature to act as a powerfulelectric brake and restore power to the line in a reverse direction.This is objectionable, and in the case of a three-wire system thecurrent thus produced may be sufiicient to operate the circuitbreaker orother protective devices of the system.

One of the objects of my invention is to overcome this difficulty, andin doing so I make use of means by which a contact-finger included inthe low-potential circuit is moved from engaging position when thecontroller is moved backward from a high to a low potential position andwhich will not make contact until the controller is turned to the OEposition and again turned forward.

Another object of my invention is to provide a novel controlling-switchby which in changing the motor connections from the low to the highpotential source the starting resistance is connected in series with themotorarmature between the high-potential mains before the armatureconnection between the low-potential mains is broken. Then the latterconnection is broken, and the resistance in the high-potential circuitis gradually out out, thus obtaining a transition from low to highpotential by gradual stages and without at any time opening themotor-circuit.

My invention also comprises other features and advantages, which will bebest understood upon reference to the following description, taken inconnection with the accompanying drawings, and the parts, improvements,and combinations which I regard as my invention will be specificallypointed out in the append: ed claims.

Referring to the accompanying drawings, Figure 1 is an elevation of acontroller embodying the features of my invention. Fig. 2 is a sectionthereof, taken on the line 2 2 of Fig. 1 and illustrating particularlythe means for operating the movable contactfinger. Fig. 3 is anelevation of the mechanism for moving the contact-finger viewed in thedirection of the arrow 3 in Fig. 2. Fig. 4: is a vertical section ofsaid means and an adjacent portion of the controller, taken on the line4: 4c of Fig. 2. Fig. 5 is a sectional view similar to Fig. 2,illustrating a modified means for moving the contact-finger fromengaging position. Figs. 6 and 7 are sections taken on the lines 6 6 and7 7, respectively, of Fig. 5; and Fig. 8 is a diagram of themotor-circuits and the controller-contacts.

Throughout these several views like characters refer to like parts.

In the said drawings, 40 designates the back plate of thecontroller-casing, and 41 the cover. Located within this casing andbearing in the end plates 42 and 43 is the controller-shaft 414:, uponwhich is located the usual cylinder 4C5, which carries the movablecontact-segments. Three of these segments S A B are shown in full inFig. 1, while the position of the others is indicated by dotted lines.The usual contact-fingers for engagement with the movablecontact-segments are mounted on a block of insulation 46, which extendsparallel to the cylinder 45. The insulating-block 46 is divided into twosections 46 and L6 The section 46" is securely fastened to the back 4E0of the controller-casing, and the section &6, which carries theuppermost contact-finger, is mounted on a pivot 457,

extending down into the section 46, and is rotatable into and out ofengaging position with the contact-segment S, as indicated by the fulland dotted line positions in Fig. 2.

and provided with the usual arc-deflectors 50, which embrace thecontact-segments and lingers when in the closed position. (Illustratedin Fig. 2.) provided with the usual notched disk5l,with which thespring-pressed lever 52 is adapted to engage to hold the cylinder 45 inits various operative positions. Atthe lower end of the cylinder 45 is ahorizontal disk 53, of insulating material, upon which is mounted arange of fixed contacts 54, with which the movable contacts 55, securedto the lower end of the cylinder 45 and in electrical con nection withthe lowermost segment T, are adapted to engage.

The movable contact-finger S may be operated in any desired manner bythe controllershaft 44, and for this purpose I have illustrated twodifferent constructions. One of these is shown in Figs. 1 to 4 and theother in Figs 5 to 7. In the former construction the pivot 47 of theinsulating-section 46, carrying the movable contact-finger, is providedwith a crank 54, which is connected at its upper end by means of atoggle composed of the links 55 and 56 to a lug 57 on theback plate of40 of the controller-casing. By the movement of the toggle toward andfrom the shaft the crank 54 is rocked, so as to move the contact-lingerS into and out of engaging position. The outward movement of the toggleis limited by a stop 63 on the togglelink 56, engaging the cooperatingstop 64 on the back plate 40, and the forward movement is limited by theantifriction-roller 62 on the toggle engaging the face 65 of theactuatingcam 59, mounted on the controller-shaft 44. Theantifriction-roller 62 is mounted on the center of the toggle at theupper end of the connecting-pivot 61. The coiled spring 58, locatedbetween a lug on the crank 54 and the lug 64 on the back plate 40,serves to carry the toggle to either limiting position when once carriedin either direction beyond the center line. Figs. 3 and 4, comprises alower portion having a projection 60, and an upper overhang: ing portionhaving a downward projection 61. The lower projection 60 engages theroller 62 to move the finger S into non-engaging position, and, ashereinafter more fully explained, is located so that in the forwardrotation of the controller-cylinder 45 it will actuate the said fingeronly after the motor connections with the low-potential source have beenmade and before the controller has reached a highpotential position. Theoverhanging projection 61, on the other hand, engages the roller 62 tomove the finger S into engaging posi- The controller is provided withthe usual pivoted pole-piece 48, carrying a blow-out magnet49 i Theupperend of the cylinder45 is i The cam 59, as clearly shown in r tionand is so located that it engages the roller only after the controllerreaches its off position and is again moved forward.

In the finger-operating mechanism (illustrated in Figs. 5 to 7) thepivot47 is provided with the laterally-projecting crank-arm 66, which isadapted to engage at its outer end with the elongated cam 67 on the disk68, secured to the controller-shaft 44. As clearly shown in Fig. 6, oneend 67 of this cam meets the disk 68 at an inclination, while the otherend of the cam is provided with an upturned lip 69, which serves toguide the end 70 of the arm 66 into the cam-groove 71 upon its innerface. From this it will be seen that in the movement of the disk 68 inone direction the end 70 of the arm 66 will engage the groove 71, asindicated by the full-line position of said arm in Fig. 5, so as to keepthe contact-finger S in engaging position, while in the return movementof the disk the arm 66 will not lie in the groove 71, but will pass overthe upper surface of the cam 67, as clearly illustrated by thedotted-line position of the arm 66 in Fig. 5, the inclined end 67 of thecam 67 serving to guide the arm 66 to the upper surface of the cam andthe lip 69 (illustrated in Fig. 7) serving to guide the arm 66 into thegroove 7,1. In this form the cam 67 is so positioned that it will holdthe fingerS in its engaging position against the force of the spring 58during the movement of the controller through the various low-potentialpositions, but will freeitjust before reaching the first high-potentialposition. This is accomplished by locating the parts so that the outerend of the arm 66 will escape past the end 67 of the cam 67 just beforethe high-potential position is reached and will be engaged by the lip 69before the first low-potential position is reached in the forwardmovement of the controller from its off position.

Referring to the diagram of Fig. 8, S A B O D E R F T designate thecontact-fingers, and the same letters, with exponents l, 2, and 3,designate the contact-segments.which are adapted to be moved intoengagement therewith. The conducting-wires of the multivoltage system(in the present case a threewire system) are connected to the contact-[ingers R S T, the negative wire being connected to the contact-fingerR, the positive (l) wire to the contact-finger T, and the neutral (i)wire to the contactlinger S. The starting resistance R is divided intosections by suitable leads, connecting with the contact-lingers A, B, C,D, and. E, the lingers A and E connecting to the same point of saidresistance. At the point 73, running from the contact-finger D, istapped a wire 72, which leads through the blow-out coil 49 to oneterminal of the motor-armature F, the other terminal of the saidarmature being connected by a wire 74 with the contact-linger F. Thefield resistance R has one end connected by a lead 7 6 to the positivewire at a point adjacent to the contact-finger T and its other end by alead 67 to the fieldwinding GR of the motor, the other terminal of saidfield-winding being connected by a wire 78 with the negativesupply-wire. The field-resistance It is divided into a plurality ofsections by suitable leads connected to the individual contacts of therange 54, located at the lower end of the controller-cylinder. Thisresistance is also divided into larger groups by leads running to thecontacts 54. The contacts 54 and 54 are adapted to be engaged by thecontacts 55 and 55 in electrical connection with the lowermost segmentT. In this diagram the row of figures from 1 to 36 just above thesegments S and A and the double row just above the contacts 54 designatecorresponding positions of the parts. For example, when the controlleris in position 4 the contact-fingers S, C, D, F, and T will be inengagement with the corresponding segments S, C, D, F, and T and thecontact 55 will be in engagement with the contact in the range 54 marked4.

In operation when the controller is moved to the first startingposition, which is that illustrated in Figs. 1 and 2, the field-windingG will be connected to the high-potential source from the positive wireto the negative wire by Way of the contact finger T, segment T, contact55, the elongated contact of the range 54, lead 67, field-winding G andlead 78, and the armature will be connected to the low-potential source,and its circuit will extend from the positive Wire to the neutral wireby way of the contact-finger T, segments T F, contact-finger F, lead 74,armature-lead 4, lead 72, starting resistance R, contact-finger A,segments A S, and contact-finger S. In this position it will be seenthat all the starting resistance is included in circuit with themotor-armature, while none of the field resistance is included incircuit with the field-Winding. In the movement of the controllerthrough the first four positions the contact 55 remains in engagementwith the elongated contact 54, so that the field-circuit remainsunchanged, but the sections of the starting-winding It are graduallycutout through the engagement of the contact-fingers A, B, C, and D withthe segments A, B, O, and D. On the other hand, in the movement of thecontroller from the fourth to the eighteenth position thearmature-circuit remains unchangedthat is, the starting resistanceremains out of circuit-while the resistance R is gradually out into thefieldcircuit. Thus throughout the entire movement of the controller fromthe first to the eighteenthposition the speed of the motor is increasedfirst by cutting out the starting resistance and then by cutting in thefield resistance. In passing from the eighteenth to the nineteethposition the armature connections are changed from the low-potentialsource to the high-potential source. This is accomplished without at anytime breaking the motor-circuit, and the construction by which this isdone, as previously pointed out, constitutes one feature of myinvention. In this movement of the controller it will be seen that thecontact-fingers E and R engage the contact-segments E and R before thecontact-fingers S and D leave the contact-segments S and D. W'hile thecontact-fingers are thus overlapped, the motor-armature is connectedbetween the positive and neutral wires without any interveningresistance and between the positive and negative wires with the startingresistance R intervening. The circuits thus established may be traced asfollows: from the positive wire to the contact-finger T,contact-segments T F, contact-finger F, lead .74, armature F, lead 72 tothe point 73. thence by one branch through the contact-finger D,contact-segments D G B A S, and contact-finger S to the neutral wire andby another branch from the point 7 8 through the resistance R,contact-finger E, contact-segments E R contact-finger R to the negativewire. A further movement of the controller-handle breaks the connectionsof the contact fingers S and D with their segments S and D, thusbreaking the branch leading from the point 73 tothe negative wire andleaving the motor-armatu re connected between the high-potential mains,with the resistance R in series. Also in passing from the position 18 to19 the c ntact 55 by engagement with the fixed contacts 54 cuts thefield resistance R out of the fieldcircuit. Thus the position 19corresponds with the position 1 and produces the same connections,except that the motor-armature is now connected between thehigh-potential mains instead of the low-potential mains. The movementsof the controller from position 19 through the intervening positions tothe position 36 produces the same variations in resistance as themovement of the controller from the position 1 to the position 18. Inother words, the movement of the controller from the position 19 to theposition 22 cuts out step by step the starting resistance R from thearmature-circuit, and the movement leaves the armature-circuit unchangedand gradually cuts the field resistance R into circuit with thefield-winding. In order to prevent the connection between thelow-potential mains upon a retrograde movement of the controller, theneutral wire is connected to the movable finger S, and, as indicatedheretofore, this finger is moved out of engaging position as soon as thecontroller is moved bei yond the last low-potential position that is,beyond the position 18and it cannot again of the controller from theposition 22 to 86 be brought into engagement until after the controllerhas been moved to the off position. When it is desired to reverse thedirection of rotation of the motor, the controller-cylinder is movedfrom the off position in a direction opposite to that heretoforeconsidered and the contact-fingers are brought into engagement with thesegments S A B C D R F at the right of the diagram, as indicated by theposition-numerals 1 2 3' 4: These segments of the controller provide forcutting out the field resistance, so that the field-excitation is alwaysa minimum, and the variation of speed is brought about bycutting out thestarting resistance R from the armaturecircuit, so that in four steps inthe reverse movement of the controller-handle the same range of speed iscovered as in eighteen steps in the forward movement.

From the above it will be apparent that many alterations andmodifications may be made in the specific structure herein disclosedwithout departing from the spirit and scope of my invention, and Itherefore do not Wish to be limited to the specific matter disclosed,but aim to cover by the terms of the appended claims all suchalterations and modifications.

What I claim as new, and desire to secure by Letters Patent of theUnited States, is

1. In a motor-control system, the combination of an electric motor,relatively low and high potential sources of supply, and switching meansoperable upon a forward movement to establish motor connectionssuccessively with said low and high potential sources of supply and upona return movement to make only a portion of said connections.

2. In a motor-control system, the combination of an electric motor, alow-potential source of supply, a relatively-high-potential source ofsupply, and a switching means operable upon a forward movement toconnect the motor-armature to said low-potential source and then to saidhigh-potential source, and upon a return movement to make only theconnection with said high-potential source.

3. In a motor-control system, the combination of an electric motor, alow-potential source of supply, a relativelyhigh-potential source ofsupply, a controlling-switch carrying fixed contacts and movablecontacts operable upon a forward movement to connect an element of themotor first to said low-potential source of supply and then to saidhigh-potential source of supply, and means for preventing a connectionwith said lowepotential source of supply upon the return movement ofsaid switch.

4. In a motor-control system, the combination of an electric motor, alow-potential source of supply, a relatively-high-potential source ofsupply, a cylindrical member carrying contact-segments, contact-fingersadapted to engage therewith, said segments and fingers being soconstructed and arranged that in the forward movement of said cylinderone element of the motor will be connected in succession to said low andhigh potential sources, and means operative upon the return movement ofsaid cylinder to move one or more of said contact-fingers out ofengaging position to prevent a connection with said low-potential sourceof supply.

5. In a motor-controller, the combination of a cylindrical membercarrying a contact-' segment, a movable contact-finger adapted to engagetherewith, and means operated by the rotation of said cylinder to movesaid finger into and out of engaging position.

6. In a motor-controller, the combination of a cylindrical membercarrying a contact segment, a springactuated contactfinger adapted toengage therewith and normally lying in engaging position, and means formoving said finger out of engaging position upon the return movement ofsaid cylindrical memher.

7. In a motor-controller, the combination of a cylindrical membercarrying a contact-' segment, a movable contact-linger adapted to engagetherewith, and means comprising a cam carried by said cylindrical memberfor moving said finger into and out of engaging position;

8. In a motor-controller, the combination of a cylindrical membercarrying contactsegments, contact-fingers adapted to engage therewith,one of said fingers being movable into and out of engaging position, andmeans comprising a cam carried by said cylindrical member constructedand arranged to retain said movable finger in engaging positionthroughout the forward movement of said cylindrical member from offposition and then to hold said finger from its engaging position untilthe off position is again reached.

9. In a motor-control system, the combination of an electric motor, alow-potential source of supply, a relatively high potential source ofsupply, a starting resistance, and controlling means constructed andarranged to connect the motor-armature in series with the startingresistance to the low-potential source, then cut out the startingresistance to increase the motor speed, then connect said resistance inseries with the armature without breaking the connection with thelowpoten tial source, then break the latter connection and gradually cutout the resistance to increase further the motor speed.

10. In a motor-control system, the combination of an electric motor, alow-potential source of supply, a relatively high potential source ofsupply, a starting resistance, a field resistance, and controlling meansconstructed and arranged to connect the field-winding in series with thefield resistance to one of said sources, and the armature in series withthe starting resistance to the low-potential source, then cut out thestarting resistance and vary the field resistance to increase the motorspeed, then connect the starting resistance in series with the armatureto the high-potential source Without breaking the connection with thelow-potential source, then break the latter connection, and then -varythe starting and field resistances to increase further the motor speed.10

In witness whereof I have hereunto set my hand this 5th day of April,1904.

HAROLD E. WHITE. Witnesses:

BENJAMIN B. HULL, HELEN ORFORD.

